Overview
EN ISO 6883:2017 - “Animal and vegetable fats and oils - Determination of conventional mass per volume (litre weight in air)” - specifies a laboratory method to determine the conventional mass per volume (also called litre weight in air) of animal and vegetable fats and oils when they are in a liquid state. The method enables reliable volume-to-mass or mass-to-volume conversion for fats used in trade, quality control and analytical reporting. Milk and milk‑derived fats are explicitly excluded.
Key topics and technical requirements
- Scope and principle
- Measures the mass of a known volume of fat in a calibrated pyknometer at a specified temperature to obtain the litre weight (kg·L⁻¹).
- Applicable only to fats in the liquid state; excludes milk and milk products.
- Apparatus
- Use calibrated pyknometers (preferred: Jaulmes type with thermometer; alternative: Gay‑Lussac type per ISO 3507).
- Maintain controlled water bath with ±0.1 °C stability and calibrated thermometer.
- Calibration and measurement
- Pyknometer calibration procedure described; calibration at 40 °C if glass expansion coefficient is known, otherwise at 20 °C and 60 °C.
- Calibration frequency: at least once per year (soda glass pyknometers: at least every 3 months).
- Test sample preparation per ISO 661 (do not filter or dry) and avoid air bubbles.
- Procedure and results
- Determination temperature must prevent crystallisation of fat.
- Results expressed as conventional mass per volume; calculation formulas and expression rules provided.
- Quality and precision
- Precision data, repeatability and reproducibility information provided based on interlaboratory tests (see normative precision section and Annex A).
Applications and users
- Practical uses:
- Converting invoiced volumes to mass for trading edible oils, vegetable fats and animal fats.
- Product specification, labelling and inventory control where volume/mass interchange is required.
- Quality control and routine laboratory analysis in oil processing and food manufacturing.
- Typical users:
- Analytical laboratories, oilseed processors, edible‑oil refiners, food manufacturers, regulatory bodies and standards laboratories.
Related standards
- ISO 18301 - oscillating U‑tube method for conventional mass per volume (alternate technique)
- ISO 661 - preparation of test sample for animal and vegetable fats and oils
- ISO 3507 - pyknometer (Gay‑Lussac) specifications
- ISO 5555 - recommended sampling methods
Keywords: EN ISO 6883:2017, conventional mass per volume, litre weight in air, animal and vegetable fats and oils, pyknometer calibration, volume-to-mass conversion, laboratory method, density measurement.